DANFORD Phyllis

Determination of Pure and Binary Volatile Organic Compounds (VOCs) Adsorption Equilibria using Dynamic Method

KOMATSU Toshiya, FUJITA Shoichi, HIMENO Shuji

Removal of volatile organic compounds (VOCs) is of significant interest in air quality control. To construct adsorption facilities, data on adsorption equilibrium and knowledge on the actual adsorption behavioral patterns are needed and can be derived by using the dynamic method. Also when developing a mixed VOC component adsorption equilibria model there is difficulty encountered in controlling the experimental conditions such as keeping the total pressure constant and controlling the gas phase ratio especially for the conventional volumetric techniques. To overcome these problems the dynamic method was used.
An original apparatus for the dynamic method was constructed and experimental studies were made on the adsorption of pure benzene and toluene and their binary mixtures at various concentrations by granular activated carbon. Reliability of this apparatus was confirmed by comparison of the pure benzene and toluene amount adsorbed with that derived from the Head-space Gas Chromatograph method. Also experimental and theoretical correlation of the adsorption equilibrium data was also carried out using Toth equation and Dubinin-Radushkevich equation and showed a good correlation of data. The benzene and toluene mixture adsorption experiments breakthrough curves showed the competitive adsorption pattern. Benzene was being displaced by toluene, which was more the strongly adsorbed compound causing the benzene curve to display a grollup phenomenonh. The experimental results were predicted using the Ideal Adsorbed Solution Theory. It can be said that the prediction agrees well with the experimental data for the benzene and toluene mixed adsorption equilibria data and was successful.